Inorganic adsorbent materials, such as molecular sieves, zeolites, etc., have long been used to remove constituents from (gaseous and/or liquid) fluids. Zeolites such as zeolites A and X are widely used in desiccating and gas treatment applications.
In many instances, the adsorbent material is used in the form of a free flowing particulate (e.g. beads) which is allowed to contact the fluid to be treated. In other instances, the adsorbent may be embedded in a rigid monolithic structure such as a honeycomb. For many applications, these forms of the adsorbent cannot be used practically. For example, in the window spacer structures disclosed in U.S. Pat. Nos. 5,177,916 and 5,255,481, the adsorbent material is loaded into an organic matrix which is then adhered to the spacer.
In many adsorbent/organic matrix composites, the adsorbent is typically incorporated into the organic matrix by mechanical mixing while the organic matrix material is in a very soft or molten state. It is generally desirable to incorporate as much of the adsorbent as possible per unit of organic matrix so as to enhance the adsorption performance of the adsorbent/organic matrix composite as well as to reduce the cost of the composite in situations where the organic material is more expensive than the adsorbent. Unfortunately, the amount of adsorbent which can be loaded into the composite is often limited by viscosity buildup which occurs during incorporation of the adsorbent as well as by a loss of workability and/or physical integrity in the resulting composite where the composite is applied to a substrate as in the above mentioned window spacer structures.
The viscosity buildup associated with commercial adsorbent molecular sieves is generally assumed to be constant and unalterable. While it might be possible to increase the adsorbent loading by developing specialized organic matrix materials or additives therefor, these alternatives likely would be expensive. Thus, there is a need for adsorbent/organic matrix compositions having high adsorbent loading for the organic matrix material selected, yet with minimal sacrifice of workability and/or physical integrity in the resulting composite.